K)5 E A R T H. 
dering the parts where the attacks nut ft have begun, and 
the,extent of-the horizontal grounds opnolite to the cliffs, 
the private hiftory of-thole fpots, which, in point of 
chronology, is the fame as that of the continent itfelf, is ea- 
fily difeovered. 1 have frequently obferved phenomena 
of that kind; and I am convinced, that every body who 
will dedicate fome time to that ftudy, will wonder why 
it has been fo often repeated by geologifts that our conti¬ 
nents are •- very old. 
In this (ketch of the temporary deftru&ive' operations 
of the 'rivers, we find, at the fame time, the origin of the 
fediments which have formed, and are (fill forming, ww 
grounds along their beds, and the reafon why that progrefs, 
which evidently has been at firft very rapid, tends now to 
ceffation. No large materials can be floated ; and as for 
their being impelled , this cannot happen except in narrow 
deep channels. But the fand is floated at firft, and it only 
fubfides when the water , having a fufficient fpace for 
fpreading itfelf, lofes its rapidity : there its accumulation 
forms new grounds along the river, which maintains its 
cotitle through them ; but that operation alfo is dimi- 
nifliing every where, as the demolitions above become 
lefs and lefs. This again may be obferved in fome parts 
of almoft every river, with circumftanccs indicate the 
beginning and the rate of the progrefs ; but I (hall confine 
myfelf to one example. The Rhine and the Mozelle, in 
coming out of narrow valleys, meet together in an open 
fpace where the town of Coklentz is fituated. I happened, 
in the year 1778, to be there at a time when a great exca¬ 
vation had been made on one of the banks of the Rhine, a 
little above the confluence of the two rivers, for the 
building of a palace. The late M. La Roche, chancellor 
of the elector of Trieft, a learned and obliging man, fu- 
perintended thefe works, which I vilited in his company ; 
and on the fpot he informed me of fome circumftances 
that had been obferved before I came there. The whole 
of the faCts concerning that place are worthy to be re¬ 
corded, as they are now covered by the thick and long- 
lafting veil of a magnificent palace. In the lower part of 
that excavation, I (aw large rounded (tones, fuch as muft 
remain in every part of the bed of a river when it ceafes 
to be boifterous. Over thofe (tones, forced out of the 
valleys by the (till raging rivers, have been laid irregu- 
lar Jlrata of fmaller and (mailer gravel, intermixed with 
fand ; and the uppermoft flrata, to a thicknefs of about 
eight feet, are mere fand. The Romans, in their conqueft 
of Germany, encamped along that part of the Rhine, 
where they have left various kinds of monuments : the 
fpot here mentioned was one of their burial places ; for 
which purpofe they had funk wells in the new ground, as 
it then exifted. Many of thofe wells, containing urns, va¬ 
rious other fcpulcbral attributes, and fome Icgion-Jlones, were 
difeovered in making the above excavation ; and I faw 
ftill on its fides, the feCtions of two of them, the contents 
of which, taken out when they were firft opened, were 
(hewn to me by M. La Roche. Thefe feCtions, which 
I could exaCtly obferve, were in the fmall gravel mixed 
with fand, and had been filled up to its level; and all 
the other wells had been found in the fame fituation : 
confequently, it is from that time that the accumulation 
of eight feet of fand has happened ; and now the river 
never rifes to the level of that fand, but in the moll ex¬ 
traordinary floods. Here then we have, not only a clear 
fucceffion of effeCts, (hewn by that of the jlrata ; but fuch 
a ftcceffibn, as anfwers perfectly to the nature of the ope¬ 
rations by which the beds of rivers have been fixed as 
they are at prefent; and an hiflorical monument is found in 
fuch a ftage of that progrefs, as precludes abfolu'tely the 
fuppofition that our continents are very old. 
I (hall now proceed, with the fame river, to the fea- 
fiore, there to meet another Roman monument, which con¬ 
tradicts many other geological hypothefes. Some geo¬ 
logifts in particular, with a view of flip porting the.opi¬ 
nion that our continents are ■ gradually demoliftied by the 
rivers , have alleged a faCt, little known in its nature, 
that of the Rhine having been prevented, by an accumu¬ 
lation of fediment, from continuing to reach the feci. Many 
important phenomena are connected with that faCt, for 
the determination of which I muft now refume, with 
more particulars, the operations going on along the fea - 
coafl, which I only (lightly lketched before. In the 
courfe of that expofition will be feen, what is the real 
faCt in refpeCt to the difeharge of the Rhine into the fea, 
and that it is totally foreign to the above-fuppofed caufe., 
Speculative geologifts have fuppefed various kinds of 
imaginary operations, as performed on our coafls ; and 
they have attributed alfo imaginary effects to real caufes. 
There are only three general operations really going on 
around our continents ; and they are fuch as exclude every 
idea of a flow change of the level of the fea, and of any 
fort of production of new continents while others are de. 
(troying : each of thofe operations having' a very decided 
character, which implies particularly, that it is tending 
to an end. The firft of them, (till performed by the fea 
on fome parts of our coafls, has been confidered by fome 
geologifts, as a caufe of deftruCtion of the continents them- 
felves, either on every coaft, or in fome particular direc¬ 
tion, according to various fyftems. That operation how¬ 
ever is nothing more than the demolidiing and fmoothing 
of what remains within the reach of the fea, of abrupt 
fe&ions of the land. For the fupport of thofe ideas, in- 
(tead of argument, pompous and terrifying deferiptions 
of (forms have been ufed; but they vanifli at the appear¬ 
ance of theory alone, as the raging waves (their acting 
caufe) die away on the (helving (hores. The fea has no 
deftructive power over coafls which do not impede its 
motions ; it could not therefore produce cliffs where there 
were none originally: it has only attacked the parts of 
the coafls, which, at the revolution which changed its 
beds, remained fteep by the rupture of flrata ; and the 
efteCt of that operation has been, and is (till in fome 
parts, the reduction of thofe cliffs into inclined planes , on 
which, when brought to a proper declivity, the operation 
is at an end. This I have before fufficiently explained. 
The fecond operation performed along our coafls is the 
gathering of the fediments carried there by the rivers : 
which effeCt has been confidered as a fign of the deffruc- 
tion of our continents by the waters running on their fur- 
face. I have refuted that idea in its principle; and, from 
what I have proved in that refpeCt, it is evident, that 
the rivers will carry lefs and lefs fediments into the fea, 
as their channels (hall be nearer to a complete (ettlement. 
The laft operation, which ftill continues on many of our 
coafts, is the waves and tides bringing up materials from 
the bottom of the fea againft the J,bore ; which has been 
confidered by fome geologifts as the productive caufe of 
our continents by flow progrefs, either all around them, 
or on one (ide, while the oppolite fide is fuppofed to be de- 
ftroying. But I have proved that this operation , by its 
nature, is alfo temporary: it takes place only on (hallow 
and moveable bottoms, and it muft ceafe when the fea, 
by thus extending the fraud, becomes deeper near it. 
Thefe three deferibed operations, 1 repeat, are the only 
general ones known to be performed on our coafls-, and 
it is very evident that they cannot.have had, at any time, 
any influence on the exiflence of our continents-, they being 
only caufes of fome alteratiotis of their boundaries: the 
firft of them, the only one that could diminifh their ex¬ 
tent, has operated very little, and in but few parts of 
our coafls ; while, in other parts, thefe have made very 
confiderable acquifltions by the two laft caufes: and as 
thefe additions to our land have been produced by degrees, 
I (hall now explain how they afford us a new kind of 
chronometer. 
Many parts of the bottom of the fea, probably the 
greateft part, confift of a very fine hard fand, incapable 
of binding by itfelf, and fo eafily moved, that, when 
brought up and dried on the ftrand, the wind blows it 
about; unlefs it mixes, near the (liore, with the clayey 
fediments of rivers. When that mixture does not happen. 
